package com.trhui.mallbook.common.rsa;


import com.trhui.mallbook.common.exception.FailureCode;
import com.trhui.mallbook.common.exception.SdkClientException;

import java.nio.charset.Charset;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

/**
 * RSA签名验签类
 * @author linqy
 */
public class RsaUtil {
    /**
     * 签名算法
     */
    public static final String SIGN_ALGORITHMS = "SHA1WithRSA";

    /**
     * RSA签名
     *
     * @param content    待签名数据
     * @param privateKey 商户私钥
     * @param encode     字符集编码
     * @return 签名值
     */
    public static String sign(String content, String privateKey, String encode) {
        try {
            PKCS8EncodedKeySpec pripkcs8 = new PKCS8EncodedKeySpec(Base64.decode(privateKey));

            KeyFactory keyf = KeyFactory.getInstance("RSA");
            PrivateKey priKey = keyf.generatePrivate(pripkcs8);

            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

            signature.initSign(priKey);
            signature.update(content.getBytes(encode));

            byte[] signed = signature.sign();

            return Base64.encode(signed);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    public static String sign(String content, byte[] priBytes, String encode) {
        try {
            PKCS8EncodedKeySpec pripkcs8 = new PKCS8EncodedKeySpec(priBytes);
            KeyFactory keyf = KeyFactory.getInstance("RSA");
            PrivateKey priKey = keyf.generatePrivate(pripkcs8);
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
            signature.initSign(priKey);
            signature.update(content.getBytes(encode));
            byte[] signed = signature.sign();
            return Base64.encode(signed);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String sign(String content, byte[] priBytes) {
        return sign(content, priBytes, "UTF-8");
    }

    /**
     * 密钥签名
     *
     * @param content
     * @param privateKey
     * @return
     */
    public static String sign(String content, String privateKey) {
        try {
            PKCS8EncodedKeySpec pripkcs8 = new PKCS8EncodedKeySpec(Base64.decode(privateKey));
            KeyFactory keyf = KeyFactory.getInstance("RSA");
            PrivateKey priKey = keyf.generatePrivate(pripkcs8);
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
            signature.initSign(priKey);
            signature.update(content.getBytes());
            byte[] signed = signature.sign();
            return Base64.encode(signed);
        } catch (Exception e) {
            throw new SdkClientException(FailureCode.SECURITY_EXCEPTION);
        }
    }

    /**
     * RSA验签名检查
     *
     * @param content   待签名数据
     * @param sign      签名值
     * @param publicKey 分配给开发商公钥
     * @param encode    字符集编码
     * @return 布尔值
     */
    public static boolean doCheck(String content, String sign, String publicKey, String encode) {
        try {
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            byte[] encodedKey = Base64.decode(publicKey);
            PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));

            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

            signature.initVerify(pubKey);
            signature.update(content.getBytes(encode));

            boolean bverify = signature.verify(Base64.decode(sign));
            return bverify;

        } catch (Exception e) {
            e.printStackTrace();
        }

        return false;
    }

    /**
     * RSA验签名检查
     *
     * @param content
     * @param sign
     * @param publicKey
     * @return
     */
    public static boolean doCheck(String content, String sign, String publicKey) {
        try {
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            byte[] encodedKey = Base64.decode(publicKey);
            PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));

            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

            signature.initVerify(pubKey);
            signature.update(content.getBytes(Charset.forName("UTF-8")));

            boolean bverify = signature.verify(Base64.decode(sign));
            return bverify;

        } catch (Exception e) {
            e.printStackTrace();
        }

        return false;
    }
}